ApoA-1/SR-BI And S1P/S1PR1 Synergistically Modulate The Anti-inflammatory Effects Through PI3K-AKT Pathway In Human Umbilical Vein Endothelial Cells

Background and purpose: As the main cause of cardiovascular disease,Atherosclerosis is not only a disorder of lipid,but also a chronic inflammatory disease,it is characterized by excessive accumulation of cholesterol in the arterial intima.Vascular endothelial injury is a key initial event in the process of occurrence and development of atherosclerosis.Treatment of human umbilical vein endothelial cells(HUVEC)with 1-sphingosine(S1P)can obviously inhibit cell apoptosis and promote cell survival,which mechanism is related to PI3K-AKT signaling pathway.SR-BI and apoA-1 combine to mediate the various functions of HDL.One of the important mechanisms of HDL combined with S1P(HDL-S1P)in vascular protection is:S1P exerts a wide range of biological effects by binding to membrane receptors(S1PR1-S1P5)of vascular endothelial cells.Studies have shown that the S1PR1 receptor has anti-atherosclerosis effect in endothelial cells,which is mediated by S1P/S1PR1 through PI3K-Akt signaling pathway.Therefore,the main purpose of this study was to investigate apo A-1/SR-BI regulates the anti-inflammatory effect of S1P/S1PR1 via PI3K-AKT pathway.Methods:Cultured human umbilical vein endothelial cells(HUVECs)were treated with different concentrations(0μM,0.1.0μM,0.25μM,0.5μM,1.0μM,1.5μM)and different time(0h,2 h,4 h,6h,12 h,24h)of S1 P.The inhibitors of S1PR1(W146),S1P2(JTE-013),S1P3(CAY10444),PI3K(LY294002),Akt(MK2206)and SR-BI(BLT-1),and transient transfection of SR-BI were applied to intervene the effects.The protein expression levels of cytokinesIL-6、IL-8 and IL-10 determined by ELISA and Western blot in cell culture medium and cell,respectively.The protein expression levels of MCP-1、ICAM-1 determined by Western blot.The nuclear translocation of NF-κB were determined by immunofluorescence.Results: The protein expression levels of cytokines IL-6 、IL-8、MCP-1 and ICAM-1 in cell culture medium and cell were significantly decreased,but IL-10 increased compared with control after treatment withS1 P and apoA-1,or transfection with SR-BI.The inhibitors W146,CAY10444,BLT-1,LY294002 and MK2206 attenuated the antagonist effect of apoA-1.Conclusions:(1)S1P/S1PR1 can mediate the anti-inflammatory effect of vascular endothelial cells.(2)SR-BI can promote the anti-inflammatory effect of S1P/S1PR1-mediated vascular endothelial cells.(3)SR-BI promotes the anti-inflammatory effect of S1P/S1PR1 on vascular endothelial cells isrelated to the SR-BI /PI3K/AKT signaling pathway.